Methods of this type are frequently employed to count or track persons or other moving objects located in a monitoring region or passing through a monitoring region. Potential fields of application include, for example, the entrance region of a building or a door of a vehicle used in passenger transportation, such as a train or bus. The image sequences are recorded by a camera for this purpose and subsequently evaluated by an appropriately equipped evaluation unit, for example, by way of image segmentation, pattern analysis, movement analysis and/or another image analysis method based on image data of the image sequence.
Typically, in addition to locating target objects, further objects, so-called interfering objects, are located within the monitoring region. These interfering objects are not ordinarily counted or tracked, but they can be reliably distinguished from the target objects. Customarily, an attempt is made to solve this problem by assigning target and interfering objects to differing movement classes. For example, the target objects to be detected, which have a typical speed, can be assigned to a first movement class, and interfering objects, which may be spatially stationary objects can be assigned to a second movement class. In the corresponding detection method, it is then possible to suppress all stationary interfering objects from the images of the image sequences using known image processing methods. Thereafter, the images of the image sequence adjusted in this way are analyzed for the presence of the target objects.
However, in many cases it is not possible to assign target and interfering objects to differing movement classes. For example, vehicle doors in buses and trains, other door types, and people are not purely stationary objects. Thus, these objects cannot be suppressed in the conventional manner described above.
It is therefore the object of the present invention to propose a method for detecting target objects in an image sequence of a monitoring region, wherein the method overcomes, or at least mitigates, the problems of the prior art. The method allows for the detection of target objects within a monitoring region. For this purpose, the monitoring region may additionally include interfering objects, which, similarly to the target objects, may be mobile. In addition, a system is proposed, which is suitable for the detection of moving target objects in a monitoring region, in which the moving target objects and moving interfering objects may be located. Finally, a transportation vehicle is proposed, wherein the vehicle is suitable for detecting and counting persons entering the vehicle or exiting the vehicle.
This object is achieved by a method having the aspects of the claims below and by a system having the aspects of the additional independent claim below. Advantageous embodiments and refinements will be apparent from the characteristics of the dependent claims.